JP2002309149A - Aqueous pigment dispersant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pigment dispersant useful as a raw material for an aqueous coating material excellent in gloss. SOLUTION: An organosiloxane-based aqueous pigment dispersant represented by structural formula (1) [wherein a, b, and c are each an integer of 0 or higher provided a+b+c>=1; and each X is independently one or more groups (R<1> ) selected from among organic hydrophobic monovalent groups containing no siloxy group, an alkoxy group, a hydroxy group, a halogen or H or is independently one or more organic monovalent groups (A) selected from among monovalent organic groups having no siloxy group and having a hydrophilic group, provided at least one of X is A] is provided. A pigment dispersion containing the dispersant is also provided together with an aqueous coating material containing the dispersant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pigment dispersant used for preparing a water-based paint.

[0002]

2. Description of the Related Art In recent years, with increasing interest in environmental issues, the conversion from paints using organic solvents to water-based paints has been promoted. In general, water-based paints are synthesized by an emulsion polymerization method and are not only harmless because the solvent of the product is water, but also synthesized in an aqueous medium. . However, water-based paints generally have lower gloss than solvent-based paints, and thus organic solvent-based paints are still widely used in fields requiring high gloss, for example, paints for architectural exteriors and automobiles.

[0003] Usually, water-based paints are preliminarily prepared with pigments, pigment dispersants,
A pigment is dispersed in water, a thickener, and the like using a disperser such as a paint shaker, a ball mill, an attritor, or a sand mill to obtain a pigment dispersion, and then mixed with an aqueous resin to obtain a paint. Various pigment dispersants have been developed for the purpose of improving the gloss of such paints. For example, JP-A-9-12664 discloses a pigment dispersant comprising a water-soluble polyaddition product containing a perfluoroalkyl group,
JP-A-9-241535 discloses a pigment dispersant synthesized from an amino acid, and JP-A-9-188732 discloses a pigment dispersant.
Organic polymer pigment dispersants having siloxyl substituents are mentioned.

[0004] These are compounds in which an organic resin polymer is used as a main chain and various functional groups are substituted in side chains thereof, but it is difficult to obtain a paint having sufficiently high gloss with such a compound. there were.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the inventors have found that a resin having a siloxane skeleton as a main chain is useful as a pigment dispersant for obtaining a paint having high gloss. And arrived at the present invention. That is, a first aspect of the present invention is an aqueous pigment dispersant characterized by being an organosiloxane represented by the following structural formula (1).

[0006]

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(Where a, b, c are a ≧ 0, b ≧ 0, c
X is an integer that satisfies ≧ 0, a + b + c ≧ 1, and X is independently selected from the group consisting of a hydrophobic monovalent organic group containing no siloxyl substituent, an alkoxy group, a hydroxy group, a halogen atom and a hydrogen atom. Not containing one or more groups (R ¹ ) or siloxyl substituents,
And one or more monovalent organic groups (A) containing a hydrophilic group, and at least one of X is A. )

The second aspect of the invention is that A in X in structural formula (1)
Is 1% or more of the first aqueous pigment dispersant of the invention. A third aspect of the invention is the second aqueous pigment dispersant of the invention, wherein the proportion of A in X in the structural formula (1) is 5% or more. A fourth aspect of the invention is the third aqueous pigment dispersant of the invention, wherein the proportion of A in X in the structural formula (1) is 50% or less. A fifth aspect of the present invention is that the hydrophilic group contained in A in the structural formula (1) is one or more groups selected from the group consisting of an anionic hydrophilic group, a cationic hydrophilic group, and a nonionic hydrophilic group. The first to fourth aqueous pigment dispersants according to the invention, characterized in that:

A sixth aspect of the present invention is the aqueous system according to the first to fourth aspects, wherein the hydrophilic group contained in A in the structural formula (1) is one or more anionic hydrophilic groups. It is a pigment dispersant. In a seventh aspect of the present invention, a hydrophilic group contained in A in the structural formula (1) is one selected from the group consisting of a carboxyl group and a group derived from a salt thereof, and a sulfonic acid group and a group derived from a salt thereof. Or the first to fourth aqueous pigment dispersants of the invention, which are two or more groups.

An eighth aspect of the present invention is that the hydrophilic group contained in A in the structural formula (1) representing the pigment dispersant is selected from the group consisting of groups represented by the formulas (2) and (3). Alternatively, the present invention provides the aqueous pigment dispersant according to any one of the first to fourth aspects, wherein the aqueous pigment dispersant is two or more groups.

[0011]

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[0012]

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(In the above formulas (2) and (3), R
² represents a substituted or unsubstituted divalent organic group or a direct bond; R ³ each independently represents a substituted or unsubstituted monovalent organic group or a hydrogen group; R ⁴ represents a substituted or unsubstituted 3 And B independently represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or a substituted ammonium represented by the formula (4). HNR ⁵ R ⁶ R ⁷ (4) (R ⁵ , R ⁶ and R ⁷ each independently represent a monovalent organic group or a hydrogen group.))

According to a ninth aspect of the present invention, the hydrophilic group contained in A in the structural formula (1) is one or more kinds of groups represented by the formula (5). 1 to 4 aqueous pigment dispersants.

[0015]

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(Wherein R ³ each independently represents a substituted or unsubstituted monovalent organic group or hydrogen group, and B each independently represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or The substituted ammonium represented by the above formula (4) is shown.)

According to a tenth aspect of the invention, the hydrophilic group contained in A in the structural formula (1) is one or more groups represented by the formula (6). 1 to 4 aqueous pigment dispersants.

[0018]

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(Wherein B is each independently a hydrogen atom,
It represents an alkali metal, an alkaline earth metal, ammonium or a substituted ammonium represented by the above formula (4). )

An eleventh aspect of the invention is the ninth aspect of the invention, wherein any one of R ^{3 in} the group represented by the formula (5) is a methyl group, and all the others are hydrogen groups. It is an aqueous pigment dispersant. A twelfth aspect of the invention is the first to eleventh aqueous pigment dispersants of the invention, wherein the molecular weight of R ^{1 in} the structural formula (1) is 200 or less. A thirteenth aspect of the present invention is that R ¹ in the structural formula (1) is one or two selected from the group consisting of an aliphatic hydrocarbon group and an aromatic hydrocarbon group.
1 to 1 of the invention, characterized in that the
2 is an aqueous pigment dispersant.

A fourteenth aspect of the present invention is an aqueous pigment dispersion containing a pigment and the first to thirteenth aqueous pigment dispersants of the invention. A fifteenth aspect of the present invention is a water-based paint comprising an aqueous resin and the fourteenth water-based pigment dispersion of the invention. A sixteenth aspect of the present invention is a base material to which the fifteenth aspect of the present invention is applied.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
At least one of Xs in the organosiloxane represented by the structural formula (1) of the present invention is a monovalent organic group A containing a hydrophilic group. If A is not present in the siloxane, it will not function at all as a pigment dispersant, nor will it mix with water at all. On the other hand, if A is present in excess, the water resistance of a coating film obtained from a paint containing the pigment dispersant will be reduced. Therefore, the proportion of A in X is preferably 1% or more, more preferably 5% or more, and even more preferably 5% or more and 50% or less.

Examples of A include an organic group having an anionic hydrophilic group, an organic group having a cationic hydrophilic group, an organic group having a nonionic hydrophilic group, and the like. These are used alone or in combination of two or more. Among these, an organic group having an anionic hydrophilic group is preferable because hydrophilicity and high gloss can be obtained with a small amount.

Examples of the organic group having an anionic hydrophilic group include a carboxyl group, a sulfonic acid group, a phenolic hydroxyl group, and an organic group having a salt thereof.
Since the pigment dispersant has good stability, among the anionic hydrophilic groups, a group containing a group derived from a carboxyl group or a salt thereof, and a group containing a group selected from the group consisting of sulfonic acid and a group derived from a salt thereof. Is more preferable. Further, those containing a carboxyl group represented by the formulas (2) and (3) and / or an organic group having a salt thereof are more preferable because of exhibiting good pigment dispersibility.

[0025]

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[0026]

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(In the above formulas (2) and (3), R
² represents a substituted or unsubstituted divalent organic group or a direct bond; R ³ represents each independently a substituted or unsubstituted 1
R ⁴ represents a substituted or unsubstituted trivalent organic group; B represents each independently a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or a compound represented by the formula (4) ) Represents a substituted ammonium. HNR ⁵ R ⁶ R ⁷ (4) (R ⁵ , R ⁶ and R ⁷ each independently represent a monovalent organic group or a hydrogen group.))

The molecular weight of the organic group containing an anionic hydrophilic group may be any. However, if the molecular weight is too large, the effect of imparting hydrophilicity by the anionic hydrophilic group may be reduced. For this reason, the molecular weight excluding the anionic hydrophilic group in A is preferably about 500 or less.

Examples of the organic group having a cationic hydrophilic group include a primary amino group, a secondary amino group, a tertiary amino group, and an organic group having a salt thereof. When the molecular weight of the organic group having a cationic hydrophilic group is large, the effect of imparting hydrophilicity may be reduced as in the case of the organic group having an anionic hydrophilic group. For this reason, the molecular weight excluding the cationic hydrophilic group in A is preferably about 500 or less.

Examples of the organic group having a nonionic hydrophilic group include organic groups having polyethylene oxide, polypropylene oxide, a copolymer of polyethylene oxide and polypropylene oxide, and derivatives thereof. These may further have an anionic hydrophilic group and a cationic hydrophilic group. More specific examples of these organic groups include the following (7), (8) and (9).

[0031]

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[0032]

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[0033]

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When R ¹ in X contains a substance having a high molecular weight, for example, a high molecular weight substance such as polyacrylate or polyolefin, the effect of the present invention for improving the gloss is reduced. Therefore, R ¹ preferably has a molecular weight of about 200 or less, and more preferably comprises an aliphatic hydrocarbon and / or an aromatic hydrocarbon.

Examples of R ¹ include methyl, ethyl, propyl, butyl, hexyl, octyl,
Non-saturated hydrocarbon groups such as nonyl group, decyl group, dodecyl group, octadecyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, cyclohexyl group and adamantyl group, propenyl group, nonenyl group, dodecenyl group, etc. Saturated hydrocarbon groups, phenyl groups, hydrocarbon groups having an aromatic ring such as benzyl group, etc., among them, methyl group, phenyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group , A nonyl group, a decyl group, a dodecyl group, a straight chain hydrocarbon group such as an octadecyl group and a phenyl group. These may be used alone or in combination of two or more.

Any one of at least one of a, b, and c in the structural formula (1) may be used.
The structure of the portion to which c is added may be a block or a random structure. When a is sufficiently larger than b and c and c is substantially 0 (silicone oil type), and when a and b are sufficiently larger than c and c
Is substantially 0 (silsesquioxane type), the adsorption to the pigment is improved, and as a result, the gloss is improved, and the silicone oil type is more preferable.

These pigment dispersants are, for example, polyorganosiloxanes (a) represented by the following average composition formula (10):
And a compound (b) having a carbon-carbon unsaturated bond and a hydrophilic group. ^{_{H p R 1 q SiO (4}} -Pq) / 2 (10) ( wherein, 0 <p <4,0 ≦ q <4, (p + q) < a 4, R ¹ is each independently a siloxyl substituent Is a group consisting of one or more selected from hydrophobic monovalent organic groups, alkoxy groups, hydroxy groups, halogen atoms and hydrogen atoms that do not contain

Examples of the polyorganosiloxane (a) represented by the average composition formula (10) include hydrogen-terminated polydimethylsiloxane, methylhydrogensiloxane-dimethylsiloxane copolymer, polymethylhydrogensiloxane, polyethylhydrogensiloxane,
Polyphenyl (dimethylhydrogensiloxy) siloxane derived from hydrogen-terminated, methylhydrogensiloxane-phenylmethylsiloxane copolymer, hydrogen ladder silicone, and trialkylsilane, dialkylsilane, alkylsilane, trihalosilane, dihalosilane, halosilane, etc. Siloxanes and their derivatives, and these can be used alone or in combination of two or more.

Examples of the compound having a carbon-carbon unsaturated bond and a hydrophilic group include allylsulfonic acid and salts thereof, styrenesulfonic acid and salts thereof, polyoxyethylene allyl ether, polyoxypropylene allyl ether, and polyoxyethylene polyether. Oxypropylene allyl ether, allylamine, dimethylallylamine, diethylallylamine, allyltetramethylpiperidine and the like can be mentioned. When a carboxyl group is introduced as an anionic hydrophilic group, the compound can be easily introduced by using a compound in which a carboxyl group is protected by an appropriate protecting group and then deprotecting. Examples of the protecting group include an alkyl ester, a silyl ester, and an acid anhydride. An acid anhydride is preferable because an unnecessary protecting group is not generated after deprotection. Examples of organic compounds having an acid anhydride group and a carbon-carbon unsaturated bond include maleic anhydride, 2-chloromaleic anhydride, dichloromaleic anhydride, 2,3-dimethylmaleic anhydride, itacone Acid anhydride, citraconic anhydride, aconitic anhydride,
Dodecenyl succinic anhydride (DDSA), nonenyl succinic anhydride (NSA), octenyl succinic anhydride, 5
-Norbornene-2,3-dicarboxylic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride (M
NA), 1,4,5,6,7,7-hexachloro-5-
Norbornene-2,3-dicarboxylic anhydride, 1,2,2
3,6-tetrahydrophthalic anhydride, 3,4,5,6
-Tetrahydrophthalic anhydride, bicyclo [2,2,
2] oct-7-ene-2,3,5,6-tetracarboxylic anhydride and derivatives thereof.
Among them, the compound represented by the formula (11) is particularly preferable because of good reactivity with the polyorganosiloxane (a). Further, 5-norbornene-2,3-dicarboxylic anhydride and methyl-5 -Norbornene-
2,3-Dicarboxylic anhydride (MNA) is more preferred because it is easily available. These can be used alone or in combination of two or more.

[0040]

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(Wherein R ³ each independently represents a substituted or unsubstituted monovalent organic group or hydrogen group, and B each independently represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or And a substituted ammonium represented by the formula (4): HNR ⁵ R ⁶ R ⁷ (4) (R ⁵ , R ⁶ and R ⁷ each independently represent a monovalent organic group or a hydrogen group.)

The hydrolysis of these acid anhydride groups is carried out after the reaction with the organosiloxane (a), preferably at 0 ° C. to 100 ° C. in the presence of an acid or base catalyst. And water.
Examples of the acid catalyst include hydrochloric acid, sulfuric acid, nitric acid, inorganic acids such as phosphoric acid, acetic acid, propionic acid, benzenesulfonic acid, paratoluenesulfonic acid, dodecylbenzenesulfonic acid,
There are organic acids such as acrylic acid, methacrylic acid, etc.,
Examples of the base catalyst include inorganic bases such as sodium hydroxide, potassium hydroxide, calcium hydroxide, and ammonia, and organic bases such as diethylamine, triethylamine, diisopropylamine, and diisopropylethylamine. Among them, the base catalyst is particularly preferable because hydrolysis proceeds rapidly at room temperature.

The above-mentioned reactions (a) and (b) can be carried out preferably at -80 ° C to 300 ° C in the presence or absence of a catalyst, in the presence or absence of an organic solvent. As the organic solvent to be used, acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ether, diisopropyl ether, dibutyl ether, ethylene glycol dimethyl ether, tetrahydrofuran, dioxane, ethyl acetate, butyl acetate,
N, N-dimethylformamide, N, N-dimethylacetamide, benzene, toluene, xylene, dichloromethane, chloroform, carbon tetrachloride and the like.

The catalyst used in this reaction is a transition metal catalyst, that is, nickel, palladium, platinum, iron, ruthenium, osmium, cobalt, rhodium, iridium,
Compounds such as chromium are suitable, especially compounds of platinum, palladium and rhodium. Examples of platinum compounds include chloroplatinic acid (IV), dichlorodicyclopentadienyl platinum (II), divinyltetramethyldisiloxane platinum (0), bis (acetylacetonato) platinum (I
I), dichloro (1,5-cyclooctadienyl) platinum (II), platinum-phosphine complex, platinum-amine complex,
Platinum-olefin complex, platinum black, platinum-activated carbon, tetramethyltetravinylcyclotetrasiloxane platinum (0), a simple substance of platinum, and the like. Examples of the palladium compound include dibenzylideneacetone palladium (0),
Bisacetylacetonatopalladium (II), bishexafluoroacetylacetonatopalladium (II), sodium chloride palladium, palladium-phosphine complex, palladium-amine complex, palladium-olefin complex, palladium chloride, palladium black, palladium-activated carbon , Palladium-alumina, simple substance of palladium, and the like. Examples of rhodium compounds include chlorotristriphenylphosphine rhodium (I) (Wilkinson complex), trisacetylacetonatotrodium (III),
Rhodium-phosphine complexes, rhodium-amine complexes, rhodium-olefin complexes and the like. These can be used alone or in combination of two or more.

In the fourteenth pigment dispersion containing a pigment and the above-mentioned pigment dispersant of the present invention, pigments that are usually used for paints and the like can be used without particular limitation. For example, carbon black, titanium oxide, zinc oxide, Prussian blue, cadmium sulfide, iron oxide, ultramarine, mica, pearl mica, inorganic coloring pigments such as chromium pigments, extenders such as calcium carbonate, barium sulfate, calcium silicate, aluminum flakes , Copper powder, metal pigments such as copper flakes, and azo lake red,
Organic pigments such as Benz Orange, Quinacridone Magenta, Benz Yellow, Phthalocyanine Blue, and Phthalocyanine Green can be used. These pigments are used alone or in combination of two or more. The aqueous pigment dispersion can be obtained by adding these pigments, the pigment dispersant, water, and, if necessary, an organic solvent and the like, stirring and mixing them, and dispersing them using a disperser. As the disperser, those generally used in the paint industry and the ink industry can be used, and examples thereof include a ball mill, a sand mill, a roll mill, an attritor, and a dissolver.

By using the pigment dispersant and the pigment dispersion of the present invention, a highly glossy water-based paint can be prepared. That is, these water-based paints are obtained by mixing the pigment dispersion and the water-based resin, or simply mixing the water-based resin and the pigment dispersion containing the pigment dispersant other than the pigment dispersant of the present invention, and the pigment dispersant. , Etc.
Examples of the water-based resin used in the present invention include a water-soluble resin and an emulsion (latex) in addition to a commercially available water-based paint. As the water-soluble resin, polyvinyl alcohol, polyacrylamide,
Examples thereof include a water-soluble acrylic polymer, a water-soluble urethane polymer, and a water-soluble fluororesin.

Examples of the emulsion include acrylic resin emulsion, acrylic silicone resin emulsion, urethane resin emulsion, fluororesin emulsion styrene / butadiene resin emulsion, acrylonitrile / butadiene resin emulsion, styrene / isoprene resin emulsion, vinyl chloride resin emulsion, Examples thereof include an ethylene / vinyl acetate resin emulsion, an ethylene / vinyl chloride resin emulsion, and a natural rubber emulsion. These can be used alone or in combination of two or more depending on the application. The acrylic resin emulsion is obtained, for example, by an emulsion polymerization method. There is no particular limitation on the method of emulsion polymerization, and the monomer, chain transfer agent, surfactant, radical polymerization initiator, and other additives used as necessary in an aqueous medium by a conventionally known method. An emulsion can be produced by polymerizing a monomer in a dispersion system containing the agent component as a basic composition component.

The base material to which the water-based paint of the present invention is applied includes nonmetallic inorganic substances such as glass, gypsum and stone, metals such as iron, stainless steel, aluminum and copper, acryl, polystyrene, and the like.
Examples include polymers such as polyester, polycarbonate, and polyolefin, synthetic rubber, natural rubber, fibers such as cotton, silk, hemp, and nylon, and wood. These may be applied directly, or a paint may be applied thereon and further applied.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples. All parts in the examples and comparative examples mean parts by weight. As a physical property evaluation test of a paint containing a pigment dispersant, first, a standard pigment dispersion (α) having the following composition and containing a commercially available pigment dispersant (Poise 530 (manufactured by Kao Corporation))
And water-based paints (β) having the following compositions containing various emulsions were prepared, and these (α) and (β) were mixed to prepare an enamel paint. Next, 4.6 parts (in terms of solid content) of a pigment dispersant to be tested and evaluated was added to this enamel paint, and the resulting enamel paint composition was added to a wire coater No. 1 50 was applied to a sulfated alumite plate and dried at room temperature for 7 days.
Measurement of 0 ° -60 ° specular reflectance (60 ° gloss value) was performed. Those having a 60 degree gloss value of 80.0 or more were judged to be acceptable.

Enamel paint composition Standard pigment dispersion (α) composition Water 82.5 parts Commercial pigment dispersant; Poise 530 (manufactured by Kao Corporation) 7.5 parts 5% by weight aqueous solution of sodium tripolyphosphate 7.5 parts Thickener; Daicel HEC SP-600 (manufactured by Daicel Chemical Industries, Ltd.) 3w% aqueous solution 25.0 parts Antifoaming agent; Nopco 1497VD (manufactured by San Nopco) 2.5 parts Titanium oxide; Department

Aqueous paint (β) composition Emulsions of each Example and Comparative Example (solid content conversion) 460.0 parts Ethylene glycol monobutyl ether 45.0 parts Ethylene glycol mono 2-ethylhexyl ether 90.0 parts Water 30.0 parts Antifoaming agent: 1.0 part of Nopco 1497VD (manufactured by San Nopco)

[0052]

Example 1 100 parts of methylhydrogensiloxane-dimethylsiloxane copolymer V-58 (manufactured by Asahi Kasei Wacker Silicone Co., Ltd.), 100 parts of dioxane, and 0.11 part of a 5% by weight isopropanol solution of chloroplatinic acid were refluxed with a cooling group, a thermometer, Put into a reaction vessel equipped with a stirrer,
While heating to 100 ° C., 100 parts of a 20% by weight solution of 5-norbornene-2,3-dicarboxylic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) in dioxane was added dropwise over 30 minutes, followed by stirring for 1 hour.
An acid anhydride group-containing polyorganosiloxane solution was obtained. To 100 parts of the synthesized polyorganosiloxane solution, 10 parts of triethylamine and 5 parts of water were added, and the mixture was stirred at room temperature for 30 minutes. Thereafter, 150 parts of water was further added, and dioxane was distilled off under reduced pressure. Pure water was added to a concentration of 25% by weight to obtain a pigment dispersant aqueous solution (A).

An evaluation test was carried out by the above-described method using Polydurex G620 (manufactured by Asahi Kasei Corporation) as the obtained pigment dispersant aqueous solution (A) and emulsion.
The results are shown in Table 1.

[0054]

Example 2 Polydurex G6 as an emulsion
An evaluation test was performed in the same manner as in Example 1 except that 33 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0055]

Example 3 Polytron E390M as an emulsion
An evaluation test was performed in the same manner as in Example 1 except that (made by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0056]

Example 4 100 parts of methylhydrogensiloxane-dimethylsiloxane copolymer V-58 (manufactured by Asahi Kasei Wacker Silicone Co., Ltd.), 100 parts of dioxane, 0.11 part of a 5% by weight solution of chloroplatinic acid in isopropanol were refluxed with a cooling group, a thermometer, Put into a reaction vessel equipped with a stirrer,
While heating at a temperature of 50 ° C., a solution of 50 parts of polyoxyethylene allyl methyl ether (PKA-5118, manufactured by NOF CORPORATION, weight average molecular weight: 800) in 33 parts of dioxane was added dropwise over about 1 hour. Next, 30-norbornene-2,3-dicarboxylic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) was added.
After 39.8 parts of a w% dioxane solution was added dropwise over 30 minutes, the mixture was stirred for 1 hour to obtain an acid anhydride group-containing polyorganosiloxane solution. To 100 parts of the obtained polyorganosiloxane solution, 200 parts of a 25% aqueous ammonia solution was added,
After stirring at room temperature for 30 minutes, dioxane was distilled off under reduced pressure.
Pure water was added so as to have a solid content of 25% by weight to obtain a pigment dispersant aqueous solution (a).

Using the obtained aqueous solution of the pigment dispersant (a) and Polydurex G620 (manufactured by Asahi Kasei Corporation) as an emulsion, evaluation tests were carried out by the methods described above. The results are shown in Table 1.

[0058]

Example 5 Polydurex G6 as an emulsion
An evaluation test was performed in the same manner as in Example 4 except that 33 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0059]

Example 6 Polytron E390M as an emulsion
An evaluation test was performed in the same manner as in Example 4 except that (Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0060]

Example 7 1,3,5,7-tetramethylcyclotetrasiloxane (LS-8600 manufactured by Shin-Etsu Chemical Co., Ltd.)
2 parts, octamethylcyclotetrasiloxane (LS-8620 manufactured by Shin-Etsu Chemical Co., Ltd.) 287.2 parts, 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane (LS-8490 manufactured by Shin-Etsu Chemical Co., Ltd.) 88.9 parts, hexamethyldisiloxane (LS-7130 manufactured by Shin-Etsu Chemical Co., Ltd.) 1
6.2 parts and 10 parts of sulfated zirconia (manufactured by Wako Pure Chemical Industries, Ltd.) were charged into a reaction vessel equipped with a reflux cooling system, a thermometer, and a stirrer, heated to 50 ° C., stirred for 3 hours, and then further heated to 80 ° C. While stirring for 5 hours. After filtering the sulfated zirconia, low boiling components were removed at 130 ° C. under vacuum to obtain 400 parts of transparent methylphenyl silicone oil <1>. 100 parts of the obtained silicone oil <1>, 100 parts of dioxane, and 0.11 part of a 5 w% isopropanol solution of chloroplatinic acid are put into a reaction vessel equipped with a reflux cooling system, a thermometer, and a stirrer, and heated to 90 ° C. As it is, methyl-5
A solution prepared by dissolving 30 parts of -norbornene-2,3-dicarboxylic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) in 100 parts of dioxane was added dropwise over 30 minutes. Thereafter, the obtained reaction mixture was stirred for 5 hours to obtain an acid anhydride group-containing polyorganosiloxane solution.

The obtained polyorganosiloxane solution 10
To 0 part, 10 parts of triethylamine and 5 parts of water were added, and the mixture was stirred at room temperature for 30 minutes. Thereafter, 150 parts of water was further added, and dioxane was distilled off under reduced pressure to remove pure water so that the solid content became 25 w%. In addition, a pigment dispersant aqueous solution (C) was obtained.
Using Polydurex G620 (manufactured by Asahi Kasei Corporation) as the obtained pigment dispersant aqueous solution (c) and emulsion,
An evaluation test was performed by the method described above. The results are shown in Table 1.

[0062]

Example 8 Polydurex G6 as an emulsion
An evaluation test was performed in the same manner as in Example 7 except that 33 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0063]

Example 9 Polytron E390M as an emulsion
An evaluation test was carried out in the same manner as in Example 7 except that (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0064]

Example 10 100 parts of methylphenylsilicone oil <1> synthesized in Example 7, 100 parts of dioxane, dichlorodicyclopentadienyl platinum (Strem Ch)
Chemicals, Inc. 5.0 parts of a 0.25 w% dioxane solution of the above in a reaction vessel equipped with a reflux cooling system, a thermometer, and a stirrer, and heated to 90 ° C., and then heated to 90 ° C., while heating 2-octenylsuccinic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.). A) A solution of 30 parts dissolved in 100 parts of dioxane was added dropwise over 30 minutes.
Thereafter, the mixture was stirred for 7 hours to obtain an acid anhydride group-containing polyorganosiloxane solution. 10 parts of triethylamine and 5 parts of water were added to 100 parts of the obtained polyorganosiloxane solution, and the mixture was stirred at room temperature for 30 minutes. Thereafter, 150 parts of water was further added, and dioxane was distilled off under reduced pressure to obtain a solid content of 2 parts.
Pure water was added to a concentration of 5% by weight to obtain a pigment dispersant aqueous solution (d).

An evaluation test was carried out by the method described above using Polydurex G620 (manufactured by Asahi Kasei Corporation) as the obtained pigment dispersion aqueous solution (d) and emulsion.
The results are shown in Table 1.

[0066]

Example 11 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 10 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0067]

Example 12 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 10 except that M (made by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0068]

Example 13 100 parts <1> of methylphenylsilicone oil synthesized in Example 7, 100 parts of dioxane, dichlorodicyclopentadienyl platinum (Strem Ch)
Chemicals, Inc. 5.0 parts of a 0.25 w% dioxane solution of the above was charged into a reaction vessel equipped with a reflux cooling group, a thermometer, and a stirrer, and the mixture was heated to 90 ° C and heated to 5-norbornene-2,3-dicarboxylic anhydride. A solution prepared by dissolving 10 parts of a product (manufactured by Wako Pure Chemical Industries, Ltd.) in 40 parts of dioxane was added dropwise over 30 minutes. After stirring for 4 hours, 32 parts of 1-hexene (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 10 minutes, and the mixture was further stirred for 2 hours to obtain an acid anhydride group-containing polyorganosiloxane solution. The obtained polyorganosiloxane solution 10
After adding 10 parts of triethylamine and 5 parts of water to 0 parts, stirring at room temperature for 30 minutes, and then adding 150 parts of water,
Dioxane was distilled off under reduced pressure, and pure water was added so that the solid content was 25 w%, to obtain an aqueous pigment dispersant solution (e).

The obtained pigment dispersant aqueous solution (e) was subjected to an evaluation test by the method described above using Polydurex G620 (manufactured by Asahi Kasei Corporation) as an emulsion.
The results are shown in Table 1.

[0070]

Example 14 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 13 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0071]

Example 15 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 13 except that M (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0072]

Example 16 100 parts of methylphenylsilicone oil <1> synthesized in Example 7, 100 parts of dioxane, dichlorodicyclopentadienyl platinum (Strem Ch)
Chemicals, Inc. 5.0 parts of a 0.25 w% dioxane solution of the above was charged into a reaction vessel equipped with a reflux cooling group, a thermometer, and a stirrer, and the mixture was heated to 90 ° C and heated to 5-norbornene-2,3-dicarboxylic anhydride. A solution prepared by dissolving 15 parts of a product (manufactured by Wako Pure Chemical Industries) in 45 parts of dioxane was added dropwise over 30 minutes. After stirring for 4 hours, 40 parts of 1-octadecene (manufactured by Wako Pure Chemical Industries) was added dropwise over 10 minutes, and the mixture was further stirred for 2 hours, and then 1-hexene (manufactured by Wako Pure Chemical Industries).
After dropping 20 parts over 10 minutes, the mixture was further stirred for 2 hours to obtain an acid anhydride group-containing polyorganosiloxane solution. To 100 parts of the obtained polyorganosiloxane solution, 10 parts of triethylamine and 5 parts of water were added, and the mixture was stirred at room temperature for 30 minutes. Thereafter, 150 parts of water was further added. To obtain a pigment dispersant aqueous solution (f).

The aqueous pigment dispersant solution (f) thus obtained was subjected to an evaluation test using Polydurex G620 (manufactured by Asahi Kasei Corporation) as an emulsion according to the method described above.
The results are shown in Table 1.

[0074]

Example 17 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 16 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0075]

Example 18 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 16 except that M (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0076]

Example 19 100 parts of methylhydrogensiloxane-dimethylsiloxane copolymer V-58 (manufactured by Asahi Kasei Wacker Silicone Co., Ltd.), 100 parts of dioxane, and 0.11 part of a 5% by weight isopropanol solution of chloroplatinic acid were subjected to a reflux cooling group, a thermometer, Put into a reaction vessel having a stirrer,
While being heated to 0 ° C., 100 parts of a 30% by weight dioxane solution of Adecaria Soap SE-10N (manufactured by Asahi Denka Co., Ltd.) represented by the formula (12) was added dropwise over 180 minutes, and then stirred for 2 hours. An acid-base containing polyorganosiloxane solution was obtained. Synthesized polyorganosiloxane solution 100
After adding 150 parts of water to the parts, dioxane was distilled off under reduced pressure, and pure water was added so that the solid content became 25% by weight.
An aqueous pigment dispersant solution (g) was obtained.

The obtained pigment dispersant aqueous solution (g) was subjected to an evaluation test by the method described above using Polydurex G620 (manufactured by Asahi Kasei Corporation) as an emulsion.
The results are shown in Table 1.

[0078]

Embedded image

[0079]

Example 20 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 19 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0080]

Example 21 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 19 except that M (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0081]

Comparative Example 1 A test was performed in the same manner as in Example 1 except that an equal amount of Poise 530 (manufactured by Kao Corporation) was used instead of the aqueous pigment dispersant solution (a) synthesized in Example 1, and the results were obtained. The results are shown in Table 1.

[0082]

Comparative Example 2 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Comparative Example 1 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0083]

Comparative Example 3 Polytron E390 as an emulsion
Evaluation tests were performed in the same manner as in Comparative Example 1 except that M (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0084]

Comparative Example 4 Example 1 was repeated except that the aqueous solution of the pigment dispersant (A) synthesized in Example 1 was replaced with an equal amount of methylhydrogensiloxane-dimethylsiloxane copolymer V-58 (manufactured by Asahi Kasei Wacker Silicone). An attempt was made to carry out an evaluation test in the same manner as described above, but V-58 was separated from the emulsion without being uniformly mixed.

[0085]

Comparative Example 5 The same procedures as in Example 1 were carried out except that an equal amount of the methylphenyl silicone oil <1> synthesized in Example 7 was used instead of the aqueous pigment dispersant solution (A) synthesized in Example 1 as the pigment dispersant. Similarly, an attempt was made to conduct an evaluation test, but the silicone oil <1> was separated without being uniformly mixed with the emulsion. In addition, as a physical property evaluation test of a paint containing a pigment dispersant prepared by another method, first, a sample pigment dispersion having the following composition containing the pigment dispersant to be tested and evaluated was prepared.

Composition of sample pigment dispersion 82.5 parts Water 25 w% aqueous solution of pigment dispersant of each Example and Comparative Example (in terms of solid content) 7.5 parts 5 w% aqueous solution of sodium tripolyphosphate 7.5 parts Thickener; Daicel HEC SP-600 (manufactured by Daicel Chemical Industries, Ltd.) 3w% aqueous solution 25.0 parts Antifoaming agent; Nopco 1497VD (manufactured by San Nopco) 2.5 parts Titanium oxide; Department

Next, a coating composition containing the sample pigment dispersion obtained and having the following composition was prepared. 50 was applied to a sulfated alumite plate and dried at room temperature for 7 days.
Measurement of 0 ° -60 ° specular reflectance (60 ° gloss value) was performed. Those having a 60 degree gloss value of 80.0 or more were judged to be acceptable.

Coating composition composition Sample pigment dispersion 500.0 parts Emulsions of each Example and Comparative Example (solid content conversion) 460.0 parts Ethylene glycol monobutyl ether 45.0 parts Ethylene glycol mono 2-ethylhexyl ether 90.0 Part Water 30.0 parts Antifoaming agent; Nopco 1497VD (manufactured by San Nopco) 1.0 part

[0089]

Example 22 Using the aqueous pigment dispersant solution (a) obtained in Example 1, a sample pigment dispersion was obtained with the above composition. An evaluation test was performed by the method described above using Polydurex G620 (manufactured by Asahi Kasei Corporation) as the obtained sample pigment dispersion and emulsion. The results are shown in Table 1.

[0090]

Example 23 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 22 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0091]

Example 24 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 22 except that M (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0092]

Example 25 An evaluation test was carried out in the same manner as in Example 22 except that the aqueous pigment dispersant solution (a) obtained in Example 4 was used. The results are shown in Table 1.

[0093]

Example 26 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 25 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0094]

Example 27 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 25 except that M (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0095]

Example 28 An evaluation test was carried out in the same manner as in Example 22 except that the aqueous pigment dispersant solution (c) obtained in Example 7 was used. The results are shown in Table 1.

[0096]

Example 29 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 28 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0097]

Example 30 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 28 except that M (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0098]

Example 31 An evaluation test was carried out in the same manner as in Example 22 except that the aqueous solution of the pigment dispersant (D) obtained in Example 10 was used. The results are shown in Table 1.

[0099]

Example 32 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 31 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0100]

Example 33 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 31 except that M (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0101]

Example 34 An evaluation test was carried out in the same manner as in Example 22 except that the aqueous solution of the pigment dispersant (E) obtained in Example 13 was used. The results are shown in Table 1.

[0102]

EXAMPLE 35 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 34 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0103]

Example 36 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 34 except that M (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0104]

Example 37 An evaluation test was carried out in the same manner as in Example 22 except that the aqueous pigment dispersant solution (f) obtained in Example 16 was used. The results are shown in Table 1.

[0105]

Example 38 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 37 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0106]

Example 39 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 37 except that M (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0107]

Example 40 An evaluation test was carried out in the same manner as in Example 22 except that the aqueous solution of the pigment dispersant (g) obtained in Example 19 was used. The results are shown in Table 1.

[0108]

Example 41 Polydurex G as an emulsion
An evaluation test was performed in the same manner as in Example 40 except that 633 (manufactured by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0109]

Example 42 Polytron E390 as an emulsion
An evaluation test was performed in the same manner as in Example 40 except that M (made by Asahi Kasei Corporation) was used. The results are shown in Table 1.

[0110]

Comparative Example 6 A pigment dispersion was prepared in the same manner as in Example 22 except that an equal amount of methyl hydrogen siloxane-dimethyl siloxane copolymer V-58 (manufactured by Asahi Kasei Wacker Silicone) was used instead of the aqueous pigment dispersant solution. However, V-58 was separated without mixing with water, and a pigment dispersion could not be prepared.

[0111]

Comparative Example 7 Instead of the aqueous pigment dispersant solution, an equal amount of methylphenyl silicone oil synthesized in Example 7 <1>
Was used to prepare a pigment dispersion in the same manner as in Example 22, but the methylphenyl silicone oil <1> was separated without mixing with water, and the pigment dispersion could not be prepared.

[0112]

[Table 1]

[0113]

As described above, the pigment dispersant of the present invention is useful for improving the glossiness of water-based paints, which has been insufficient in the past.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 7/12 C09D 7/12 201/00 201/00 F-term (Reference) 4D077 AB03 AC05 BA02 BA07 BA13 BA14 BA15 DD56Y DE07Y DE08Y DE09Y DE29Y DE34Y 4J037 CB23 CC28 CC29 DD24 EE28 EE43 FF09 4J038 DL042 DL052 DL072 DL082 DL092 DL142 EA011 JC32 JC33 JC35 JC36 KA08 MA10 NA01

Claims (16)

[Claims] 1. An aqueous pigment dispersant, which is an organosiloxane represented by the following structural formula (1). Embedded image (Where a, b, and c are a ≧ 0, b ≧ 0, c ≧ 0, a + b
+ C ≧ 1 and X is each independently selected from the group consisting of a hydrophobic monovalent organic group not containing a siloxyl substituent, an alkoxy group, a hydroxy group, a halogen atom and a hydrogen atom. Two or more groups (R
¹ ) or one or more monovalent organic groups (A) containing no hydrophilic group and containing no siloxyl substituent, and at least one of X is A. ) 2. The ratio of A in X in the structural formula (1) is 1%.
2. The aqueous pigment dispersant according to claim 1, wherein: 3. The proportion of A in X in the structural formula (1) is 5%.
3. The aqueous pigment dispersant according to claim 2, wherein: 4. The ratio of A in X in the structural formula (1) is 50.
%. The aqueous pigment dispersant according to claim 3, wherein 5. The hydrophilic group contained in A in the structural formula (1) is one or more groups selected from the group consisting of an anionic hydrophilic group, a cationic hydrophilic group, and a nonionic hydrophilic group. The aqueous pigment dispersant according to any one of claims 1 to 4, wherein 6. The aqueous pigment dispersant according to claim 1, wherein the hydrophilic group contained in A in the structural formula (1) is one or more anionic hydrophilic groups. 7. A group in which the hydrophilic group contained in A in the structural formula (1) is derived from a carboxyl group and a salt thereof, and
The aqueous pigment dispersant according to any one of claims 1 to 4, wherein the aqueous pigment dispersant is one or more groups selected from the group consisting of a sulfonic acid group and a group derived from a salt thereof. 8. The method according to claim 1, wherein the hydrophilic group contained in A in the structural formula (1) is one or more groups selected from the group consisting of the groups represented by the formulas (2) and (3). The aqueous pigment dispersant according to claim 1, wherein the dispersant is an aqueous pigment dispersant. Embedded image Embedded image (In the above formulas (2) and (3), R ² represents a substituted or unsubstituted divalent organic group or a direct bond, and R ³ represents each independently a substituted or unsubstituted monovalent organic group or hydrogen. R ⁴ represents a substituted or unsubstituted trivalent organic group; and B independently represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or a substituted ammonium represented by the formula (4). HNR ⁵ R ⁶ R ⁷ (4) (R ⁵ , R ⁶ , and R ⁷ each independently represent a monovalent organic group or a hydrogen group.)) 9. The method according to claim 1, wherein the hydrophilic group contained in A in the structural formula (1) is one kind or two or more kinds represented by the formula (5). Water-based pigment dispersant. Embedded image (Wherein R ³ each independently represents a substituted or unsubstituted monovalent organic group or hydrogen group, and B represents each independently
It represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or a substituted ammonium represented by the above formula (4). ) 10. The method according to claim 1, wherein the hydrophilic group contained in A in the structural formula (1) is one or more groups represented by the formula (6). Water-based pigment dispersant. Embedded image (In the formula, B independently represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or a substituted ammonium represented by the above formula (4).) 11. The aqueous pigment dispersion according to claim 9, wherein one of R ^{3 in} the group represented by the formula (5) is a methyl group, and all others are hydrogen groups. Agent. 12. The molecular weight of R ^{1 in} the structural formula (1) is 20.
The aqueous pigment dispersant according to any one of claims 1 to 11, wherein the amount is 0 or less. 13. The method according to claim 1, wherein R ¹ in the structural formula (1) is one or two or more groups selected from the group consisting of an aliphatic hydrocarbon group and an aromatic hydrocarbon group. 13. The aqueous pigment dispersant according to item 12. 14. An aqueous pigment dispersion containing a pigment and the aqueous pigment dispersant according to claim 1. Description: 15. A water-based paint comprising a water-based resin and the water-based pigment dispersion according to claim 14. 16. A substrate coated with the water-based paint according to claim 15.